Pipe mold vibrator



Feb 11, 1958 c. w. CHANLUND ET AL 2,822,598

PIPE MOLD VIBRATOR Eval.

Filed May 9, 1955 5 Sheets-Sheet l 646.4 W m4n/.4 afm Feb. 11, 1958 c.w. cHANLUND ETAL 2,822,598

PIPE MOLD VIBRATOR Filed May 9, 1955 15 Sheets-Sheet 2 J6 o l 67`V BY 29.we @MM/L Feb. 1l, 1958 c. w. CHANLUND r-:TAL 2,822,598

PIPE MOLD VIBRATOR Filed May 9, 1955 5 Sheets-Sheet 3 rraeA/fyf.

PIPE MLD VIBRATOR Carl W. Chanlund, Nampa, Idaho, and Stephen R.Hubbard, Compton, Calif., assignors to Cen-Vi-Ro Pipe Corporation, SouthGate, Calif., a corporation of Delaware The invention relates tomachinery for the fabrication of concrete pipes by use of a hollowcylindrical mold spun at relatively high speeds wherein concrete whilestill in a plastic state is deposited evenly throughout the interior ofa mold and there held in position while being compacted. The inventionherein presented is an improvement upon the invention set forth inPatent No. 2,671,260.

To use dry mix of concrete in spinning molds for concrete pipe toreplace the employment of wet concrete previously used raises problemsnot met in other types of concrete work. Because of the fact thatconcrete pipe sections are relatively thin and because articles such asconcrete pipes are made in large sizes and must stand transportation andsomewhat rough handling, it is nevertheless a great advantage toincrease the strength of such articles by reduction of the water cementratio. Difficulty in distributing dry concrete mix about the interior ofa spinning cylindrical mold is one of the elements needful ofconsideration. Drawbacks which have been present in spinning moldmachines heretofore used such, for example, as the undue wear upon themoving parts and excessive noise in operation, are accentuated to astill greater degree when a dry mix is attempted to be used.

It is therefore among the objects of the invention to provide a new andimproved spinning mold pipe machine which incorporates a vibrator lsodesigned and so located as to permit a desirable mix of dry concrete tobe used in spinning molds of the type currently employed.

Another object of the invention is to provide a new and improvedconcrete pipe fabricating machine which makes use of a spinning moldwherein the mold is adapted to be effectively vibrated during theplacement of relatively dry concrete in such fashion that the majorportionof the vibrating energy is imparted to the mold without anysubstantial amount of vibration `b einginduced in the base and supportfor the mold or in the driving mechanism.

Still another object of the invention is to provide a new and improvedvibrating means for spinning concrete pipe machines wherein thevibrating portion of the device is mounted in such fashion that there isa balance resulting under vibration between the mold and the vibratorwhereby the maximum beneficial elect may vbe secured from thevibrational operation in response to a moderate expenditure of energyfor the production of the vibrational effect.

States Patent() Still another object of the invention is to provide anew l and improved vibrating device Yfor spinning molds which isrelatively simple in construction and adapted to be advantageouslylocated with respect to the moldV and the base upon which the mold ismounted and moreover which is of such construction that it can bereadily ad` j justed to impart vibration of diiferent character as occa-2,822,598 Patented Feb. 11,1958

ice

Still further among the objects of the invention is to spinning concretemolds which is adapted to be adjusted for maximum elfectiveness andwhich includes belttensioning means for the exible belt drive on thevibrator so constructed and operated as to make possible changing thetension of the belt drives without any displacement of fixed location ofthe pulleys and the shafts upon which the pulleys are mounted.

Still further among the objects of the invention is to provide a new andimproved belt tensioning mechanism by means of which an arm, theopposite ends of which serve to locate relative positions of pulleys,can be varied as to its eifective length thereby to change the tensionon a belt extending over the pulleys, which extension is also possibleof achievement by simple and positive acting means which makesunnecessary any other shift or change in the structure or operativeparts of the device.

Also included among the objects of the invention is to provide a machinewhich employs one or more unique vibrating members which impart acontrolled high-frequency vibration to the concrete mold as the mold isspun, the invention being one making possible use of relatively dryconcrete in the production of pipes of uniform con- Figure 2 is alongitudinal sectional view taken on the line 2--2 of Figure l.

Figure 3 is a longitudinal sectional View taken on the line 3 3 ofFigure 1.

Figure 4 is a cross-sectional view taken on the line 4--4 of` Figure 2.

Figure 5 is a cross-sectional view taken on the line 5--5 of Figure 6.

Figure 6 is a plan view of the end of the vibrator arm which is mountedupon the stationary support, partly broken away, and showing thecushioned connection by means of which the positioning device isfastened to the vibrator arm.

|In the embodiment chosen for the purpose of illustration there is shownin fragmentary .sectional form a concrete pipe mold 9 of a type commonlyused in spinning 'mold-S. The mold is of relatively great circumferenceas compared -with the portions of the device forming the subject matterof the persent invention and is designed to be supported by means ofpairs of trunnions at opposite ends of the mold, one pair comprisingtrunnions 11 and 12, as shown in Figure l, each of which is equippedwith an inated rubber tire 13. The trunnions are located on oppositelsides of a center line running along the bottom lof the moldsufficiently far so that they form a broad support, the treads of thetire being ,directly in'contact with an exterior surface 10 o f the moldand being adapted to absorb and cushion movement of the mold up and downas the operation progresses. Details of a typical machine are shown anddescribed in Patent 'Y 4 No.` 2,671,260.

The lmold is adapted vto be supported on a base or Vframe which issuggested schematically as baseportions 14, 15 and 16.

The vibrating device or vibrator assembly maybe described asconstituting in general a vibrator arm or vibrator support arm indicatedgenerally by the reference character 17. The arm is secured to asuitable pair of brackets 18 in turn welded upon a supporting'shaft 19which Imay be considered as mounted upon the base at the portion 16 bysome suitable fixture 2t). The pair of brackets 18 support a cylindricalcase 21v having a cylindrical bore 22 therethrough in which is located abearing sleeve 23. On the interior of the bearing sleeve is acylindrical bearing aperture 24, the axis of which is substantiallyconcentric with the cylindrical case 21. The axis is identified by thereference character 25.

Within the bearing sleeve is an eccentric sleeve 26 having a bore 27extending therethrough located such that an axis 28 of the bore iseccentric relative to the axis`25. Located as described the eccentricsleeve has a wide portion 29 on one side and a relatively narrowerportion 30 on the opposite side.

In the bore 27 is a pivot or support shaft 31 of special construction.The support shaft is keyed non-rotatably to the bearing sleeve by meansof a key 32.

The arm 17 heretofore referred to more properly comprises a pair of flatmembers 33 and 34 which are parallel to each other and which have holes35 adapted to slide over the circumference of the support shaft 31 atopposite ends. The support shaft is provided with a pair of annulargrooves 36 adapted to receive each a retention screw 37 provided with alock nut 38 bearing upon an annular enlargement 39. In this fashion thevibrator support arm is firmly anchored upon the support shaft in aposition permitting the unanchored end of the arm to move up and downpivoting about the axis 25. An adjusting nut 40 is -welded to one end ofthe support shaft and inasmuch as the support shaft is keyed to theeccentric sleeve 26, rotation of the support shaft by means of the nut40 is adapted to rotate the eccentric sleeve 26 within the bearings 23.

At the free end of the arm 17 there is provided a substantiallyrectangular opening -45 which is surrounded by a frame 46 within whichthe vibrator is carried. The frame, which may be a part of the arm, islined with layers of vibration-absorbing pads or sheets '47, V48, 49 and50. As seen in Figure 3 there is a frame 46 on each ,side each providedwith the herein described pads or sheets such that there is a balancedsupport on opposite4 sides of the vibration assembly. Guards 51 and 52may be employed to properly confine the upper and lower sheets 50 and48, respectively.

The vibrator mounting may be described as constituting a housing or body53 having a cup-like pocket 54 therein and on one side of which is anextension 55. The extension 55 is preferably rectangular'in form andpossessed of sides adapted to t respectively against the pads or sheets47, 48, 49 and 50. A flange 56 also rectangular in form is adapted toengage and be supported by the pads or sheets 47, 48, 49 and 50 of theopposite flat member 34. The iiange 56 has an edge 57 adapted to snuglyseal the pocket 54 so that the interior may be packed with oil foreffective operation. A vibrator shaft 58 is mounted in bearings 59 and60 located respectively in the body 53 and the flange 56. An eccentricweight 61 is keyed to the vibrator shaft and provides the means by whichvibration is created when the shaft is rotated. A stub shaft 62 extendsoutwardly of the vibrator shaft and has keyed thereon a pulley 63 bymeans of a key l64. VWhen the vibrator shaft and eccentric weight 61 isrotated, vibrations are transmitted to the body 53 and then carriedthrough a bracket 65 to a roller 66 which may be describedas a vibratingroller. The roller is mounted by means of a bearing 67 on a roller pin68 secured to the bracket by means of a nut 69.U As will be noted froman inspection of Figure l, the roller is adapted to roll against thecircumference 'of the pipe mold when the mold during its rotation isstruck by the 7 .vibratineollaz i 'For operating the vibrator there isprovided an electric motor 70 mounted by means of adjustable legs 71 toa portion 15 of the base. The base may be slotted following conventionalpractice to permit the motor to be adjusted up or down to vary lthetension on belts 72. The belts 72 are reeved aroundan idler pulley 73which is mounted by means of bearings 74 upon a stub shaft 7S which ispart of the structure of the support shaft 31. -It should be noted inparticular that the axis of rotation of the stub shaft 75 is coincidentwith the axis 25 which is the center of the bearing sleeves 23.

yBelts 76 which are also reeved around appropriate grooves in the idlerpulley extend around the driven pulley 63 which is keyed to the vibratorshaft.

Occasions may require the free end of the vibrator arm to be moved up ordown depending upon the diameter of the mold 9 which chances to be usedwith the machine. To thus position the end of the vibrator arm and hencethe vibrator there is provided a hydraulic ram indicated generally bythe reference character 80. The ram comprises a cylinder 81 pivotallysecured to a bracket 32 on a portion 14 Vof the base. A uid pressureline 83 supplies duid under pressure to the cylinder. A piston rod 34extends upwardly from the ram and is pivotally secured by a pin 85 to atorque bushing indicated generally by the reference character 86. Thetorque bushing is secured to the ilat members 33 and 34 of the arm 17.By injecting pressure into the pressure line 83, the piston rod 84 willbe raised thereby to elevate the position of the vibrator roller 66. Tolower the roller, the pressure may be reduced. f

The torque bushing herein selectedfor incorporation into'the vibratingdevice comprises `a pair rof franges 87 secured to the respective flatmembers 33 and 34. Slots 8S are provided in the llanges so that theattachment of .the flanges may be initial-ly adjusted to a degreelimited bythe lengths of the slots when bolts 89 are tightened. A hollowshaft'9il is Welded to the flanges 87 forming the central'portion of thetorque bushing. Surrounding the hollow shaft '96 is -a rubber sleeve 91,the sleeve being confined in position by employment of a sleeve orbushing 92. An ear flange 93, arcuate in form, extends `around thebushing and is bolted thereto by means of bolts 94. A key assists in theinterconnection of the ear ange with the bushing anchoring them againstrotation one With respect to the other. An ear 96 on the ear flangeconnectsV with a shackle 97 `at the upper end of the piston rod 84 bymeans of the pin 85.

In operation the pipe mold 9 is loaded on the trunnions 11 and 12 readyfor reception of the plastic concrete which will be vibrated during thespinning operation. While the pipe mold is rotated in accordance withconventional practice, the vibrator is adjusted to a point where thecircumference of the roller 66 is positioned in hrm contact with theexterior surface of the pipe mold. The positioning is accomplished bymeans of the hydraulic or pneumatic ram 80 operated by pressure in thepressure line 83. -After the vibrator has been positioned, the motor 70is started and the belt 72 rotates idler pulley 83, the rotation ofwhich is transferred through belts '76 to the driven pulley 63 on thevibrator shaft. This causes the eccentric Weight 61 to vibrate andvibrations are set up in the body 53 of the vibrator. These vibrationsare transferred to the roller 66 'and lthe roller beats upon thecircumference of the pipe mold 9 at the rate of vibration establishedand with vibrations of predetermined amplitude. The major portion of thevibrational energy is transferred to the pipe mold and pneumatic tires13 preferred therefrom to any portion of the framework.

Moreover, the sheets or pads 47, 48, 49 and 50 prevent the transferofvibrational energy to the vibrator arm 17.V The transfer of vibrationalenergy is therefore pre- .vented from thevibrator to the base or framethrough the vibrator v The torque bushing isfinstrumental in insuringagainst transmission of vibrational energy to the fluid system. Althoughthe sheets of rubber-like material or pads 47, 48, 49 andSt have adampening eect upon vibration, nevertheless, the arm 17 will vibrate upand down. Movement of the arm up and down is transferred to the flanges87 and to' the shaft 90. By being confined between the shaft 90 and thebushing 92 considerable friction exists between the contacting surfaces.Vibration in the shaft 90 Will be dampened by the rubber sleeve 9ibefore reaching the bushing 92 and hence the connection to the ram andthe fluid pressure system.

During the course of very strenuous usage of apparatus of the kindherein described under the conditions imposed upon it by the usualoperation, there may be a tendency for the belts 72 and 76 to loosen. Toincrease the tension on the belts 76, for example, it is necessary onlyto place a wrench on the nut 40 and by that means rotate the pivot shaft31 and hence the eccentric sleeve 26. Rotation of the eccentric sleevecauses the wide portion 29 to shift in its `location and when the wideportion is moved toward the left, Ias viewed' in Figures l and 6, theaxis 28 will be moved toward the right as the shaft 31 is rotated. Thiswill cause the arm i7 to be moved toward the right, carrying with it thestub shaft 62 of the driven pulley 63, the shift therefore causing thelbelts 76 to become tighter. It should be noted in this connection,moreover, that the axis of the shaft 75 and hence the center ofrotation` of the idler pulley 73 is not shifted because it is coincidentwith the `axis 25 which is the axis of rotation of the circumference ofthe eccentric sleeve 26. Hence there` will be no alteration of thetension in the belt 72. These belts can be tightened if need be byshifting the position of the motor 70 downwardly as viewed in Figurel'on the portion 15 of the base which is sloped for that purpose.

Important in the construction and arrangement of the vibrator is theselection of cushioning means embodied in the pneumatic tires 13, andsheets or pads, 47, 48, 49 and 50, and the torque bushing. Thesevibration dampers are selected in accordance with thevibration-inducingeccentric weight 61 and the ability of the power source, namely, themotor 7i), torotate the eccentric weight. The cushion or dampenedconnectionsreferred to may properly be described as dynamic couplingsVforming a system involving the masses of the various vibrating parts andfrictional damping. The amplitude of vibration will depend upon certainconstants in the system well known to those skilled in the art, and'bytaking those factors into consideration Yin theV structure hereindisclosed a desired amplitude of vibration can be achieved which will beselected to produce best results in the placement of concrete in thepipe mold. The roller 66 does not impart any frictional drag ron ythepipe mold inasmuch as it is free to rotate whenever contact is madeduring the vibration.

There has laccordingly been described herein a simple vibrator systemwhich is rugged in construction so as to be capable of prolonged usedfor the fabrication of pipe in production quantities and which inparticular, by balancing masses subject to vibrational effect, makeseffective use of vibration with a minimum of disadvantages.

While We have herein shown and described our invention in what we haveconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of ourinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:

l. In a molding machine having a mold for plastic material thecombination of a vibrator device for the mold, a base for mounting themold and the vibrator Sii device,` a'support'arm pivotally secured'ftothefliaseandl extending to aposition adjacent'V theV mold, a positioner`for the arm' comprising mutually extensible elements and' havingone'element thereof mounted on' the base Yarid the other elementthereof'attached to the4arm','a damper intermediate endsofsaid lastidentified element, a vibrator frame on a free end of said arm,vibration-absorbing means between. the frame 'andthe arm, a vibrationgenerator mounted on the frame, a vibrating element on the framepositioned in vibrating relationshipl with the mold, a source of poweron the base and a drive train of vibration dampingV material from saidsource of power ,tol the vibration generator.

2. In-a molding machine having a rotating moldv for plastic` materialthe combination of a vibratordevice for the mold, a" base for mountingthe mold and the vibrator device', a support arm pivotallyfsecured tothe base' and extending beneath the mo1d,7a positioner for thearmcomprising a Huid pressure ram including mutuall'yfextensibleelements'and having a stationary element thereof mounted onthe base andamovable element'thereof attached to the arm intermediate ends of thearm, aA cushionintermediate ends of said movable elernennav vibratorframe on a free end of said arm, vibration-absorbing means between theframe and the arm, a-'vib'rator shaft rotatably vmounted on the frameand an veccentric weight on said shaft, a vibratingelement on the framepositioned in vibrating relationship with the mold,l a source of poweron the base and a multiple vibration damping flexible drive from saidsource of power to the shaft.

3. In a centrifugal pipe molding machine'comprising a base, asubstantially cylindrical mold rotatably mounted on the base andpresenting a smooth cylindrical exterior portion, and resilienttrunnions resiliently and 'rotatably supporting said mold on the base,the combination of a vibrator device for the mold -comprising an armpivotally supported on the base and extending to a position-adjacent'themold and transverse to the axis thereof, said arm comprising spacedparallel parts, a connecting shaft between said arms intermediateoutside `and inside ends, an extensible positioner for the armcomprising a stationary element mounted on thebase and a movable elementsecured to thefarm, a vibration damping bushing surrounding saidconnecting shaft and ja bushing having an ear ange thereonsurrounding'rsaid vibration ldamping bushing, means attaching said earflange to said movable element, a vibrator frame mounted on the arm,vibrationabsorbingmeans between theframe-and thearm, a vibrator shaftrotatably mounted'on the'frame and an eccentric weight on said shaft,said shaft being positioned with the axis thereof parallel to the axisof the mold, a vibrating roller rotatably mounted on the frame forvibration therewith, said roller being positioned in vibrating androlling relationship with the cylindrical exterior portion of the mold,power means on the base and a drive from said power means to said shaft.

4. In a centrifugal pipe molding machine comprising a base, asubstantially cylindrical mold rotatably mounted in horizontal positionon lthe base and presenting a smooth cylindrical exterior portion, apair of trunnions on opposite sides of each end of said mold andresilient circumferential portions on said trunnions resiliently androtatably supporting said mold on the base, the combination of avibrator device for the mold'comprising an arm pivotally supported onthe base and extending beneath the mold and transverse to the axisthereof, an extensible I positioner for the arm comprising a fluidpressure ram including a stationanry element and a movable element, saidstationary element being pivotally mounted 4on the base and said movableelement being pivotally secured to the arm intermediate the fixed andmovable ends, a vibrator frame mounted on the free end of the arm,vibration-absorbing means between the frame and the arm, a vibratorshaft rotatably mounted on the frame and an eccentric weight on saidshaft, a vibrating roller rotatably mounted on the frame for vibrationtherewith, said roller being positioned in Vibrating and rolling rela-Vtionship with the cylindrical exterior portion of the mold, rotatingpower means on the base and a multiple exible drive train of vibrationdamping belting from said power means to said shaft.

5. In a centrifugal pipe molding machine a base, a substantiallycylindrical mold rotatably mounted on the base, and resilient rotatabletrunnions on the base supporting the mold, the combination of a vibratordevice for the mold comprising an arm extending to a position adjacentthe mold, a positioner for the arm comprising a portion thereof mountedon the base and another portion secured to the arm and adapted to shiftsaid arm toward and away from the mold, a vibrator frame on the arm, avibrator shaft mounted on the frame having a driven pulley thereon, adriving pulley mounted on the base with the center of rotation at afixed position, a exible belt drive between said pulleys and means foradjusting the tension on said drive comprising a casing on the basehaving a bearing aperture adjacent the driving pulley, said aperturehaving an axis coincident with the axis of the driving pulley, aneccentric member in said aperture having a bore therethrough with theaxis of the bore offset with respect to the axis of said aperture, saidarm being rotatably mounted on the eccentric member, said eccentricmember having a driving pulley stub shaft thereon concentric with theaxis of said aperture, and drive means enabling rotation of saideccentric member whereby to extend said arm and said vibrator shaft andto shift the axis of the driven pulley relative to the driving pulleywithout shifting the axis of the driving pulley.

6. In a centrifugal pipe molding machine a base, a substantiallycylindrical mold rotatably mounted on the base, and resilient rotatabletrunnions on the base supporting the mold, the combination of avibratorV device for the mold comprising an arm'extending to a positionadjacent the mold, a positioner for the arm comprising a portion thereofmounted on the base and another portion secured to the arm and adaptedto shift said arm toward and away from the mold, a vibrator frame on thearm, a vibrator shaft mounted on the frame having a driven pulleythereon, a driving pulley mounted on the base With the center ofrotation at a fixed position, a llexible vibration damping belt drivebetween said pulleys and means for adjusting the tension on said drivecomprising a casing on the base having a bearing yaperture adjacent theidler pulley, said aperture havingV an axis coincident with the axis ofthe idler pulley, an eccentric member :comprising an eccentric sleeve insaid aperture having. a bore therethrough with the 'axis of the boreoffset with respect to the axis of said aperture, a pivot shaft havingan enlarged portion Within the eccentric sleeve and non-rotatably keyedthereto, said arm being rotatablyr mounted on the eccentric member, saidpivot shaft having a driving pulley stub shaft thereon concentric withthe axis of said aperture, and means enabling rotation of said eccentricsleeve whereby to extend the arm toward its free end and to shift theaxis of the driven pulley relative to the driving pulley.

7. In a centrifugal pipe molding machine a base, a substantiallycylindrical mold rotatably mounted on the base in horizontal position,and a pair of resilient rotatable trunnions on the base supporting eachend ofthe mold, the combination of -a vibrator device for the moldcomprising an arm extending beneath the mold, a positioner for the armcomprising a portion thereof mounted on the base and another portionsecured to the arm and adapted to shift said arm toward and away fromthe mold, a vibrator frame on the free end of said arm havingvibration-absorbing means separating said frame from the arm, a vibratorshaft mounted on the frame having a driven pulley thereon, an idlerpulley mounted on the base with the center of rotation at a fixedposition, a ilexible belt drive between said pulleys and means foradjusting the tension on said drive comprising a casing on the basehaving a bearing aperture adjacent the idler pulley, said aperturehaving an axis coincident with the axis of the idler pulley, aneccentric sleeve in said aperture having a bore therethrough with theaxis of the bore oset with respect to the axis of said aperture, a pivotshaft having an enlarged portion within the eccentric sleeve andnonrotatably keyed thereto, said arm being rotatably mounted on theenlarged portion exterior of the casing, said pivot shaft having a drivepulley stub shaft thereon concentric with the axis of said aperture, andmeans enabling rotation of said eccentric sleeve whereby to shift thearm endwise and to shift the location of the axis of the driven pulleyto a different distance relative to the idler pulley Without shiftingthe axis of the idler pulley.

References Cited in the le of this patent UNETED STATES PATENTS1,580,308 Lawson Apr. 13, 1926 2,671,260 Jessen et al. Mar. 9, 19542,691,553 Pettigrew Oct. 12, 1954 2,724,582 Huff Nov. 22, 1955

